Air crash investigation agency to cut staff by about 20 per cent

Australia's air crash investigation agency is to cut its staff by up to 20 per cent.

As the search continues for the Malaysian Airlines flight missing between Malaysia and China, the Australian Transport Safety Bureau is set to tell its 110 workers that at least 20 of them must go.

Unions are demanding that frontline safety inspectors will be quarantined from the cull, which is being blamed on the "efficiency dividend" cost-cutting hitting most government departments.

The bureau is the federal government's lead agency for the investigation of air, rail and shipping accidents, near-misses and safety flaws. The ATSB's staff of about 110 includes about 60 air, sea and rail safety investigators, mostly based in Canberra but some working from field offices in Brisbane, Adelaide and Perth.